Recently, with the rapid development of economy, people are increasingly better off and, in addition to pursuing material enjoyment, pay more and more attention to recreational activities, one very popular example of which is the barbecue. Typically held outdoors, barbecues are a perfect activity in which family members or group members can take part and which therefore serves both recreational and social functions. Generally speaking, if one side of the food being barbecued is left facing the heat source for a long time, this side of the food is very likely to be overheated or even charred while the side facing away from the heat source is undercooked due to insufficient heating. In order to heat each part of the food evenly, the one in charge of grilling (hereinafter referred to as the user) has to turn the food on a regular basis.
As the manual side-turning operation in grilling requires the user to be attentive to the heated state of each piece of food being grilled and turn the different pieces one after another in a timely manner, the grilling process not only is laborious but also keeps the user from participating in other activities at the same time. In consideration of this, the inventor of the present application devised a “rotating grill rack”. This rotating grill rack, schematically shown in FIG. 1 of the present application and generally indicated by the reference numeral 1, includes a rotating rod 11, a metal frame 12, and a supporting frame 13. The rotating rod 11 has one end connected to the output shaft of a motor and the other end fixedly provided on the metal frame 12 so as to position the metal frame 12 above a heat source. The metal frame 12 has two opposite ends each formed with two slide grooves 120, and all the slide grooves 120 are parallel to one another. The supporting frame 13 is configured for receiving food therein and has two opposite ends each provided with two insertion rods 130. The insertion rods 130 are respectively and movably engageable in the slide grooves 120. When the motor is in operation, the rotating rod 11 drives the metal frame 12 to rotate clockwise. Once the metal frame 12 has been rotated by more than 180 degrees, each insertion rod 130 slides along the corresponding slide groove 120, which is tilted, and falls to the opposite end of the corresponding slide groove 120. Thus, as shown in FIG. 1, each 180-degree rotation of the rotating grill rack 1 automatically turns upward the side of the supporting frame 13 that has been facing the heat source, allowing the other side of the supporting frame 13 to face the heat source by turns. Now that the rotating grill rack 1 can rotate automatically and continuously, the user is spared a lot of work.
However, the rotating grill rack 1, though capable of automatic rotation to heat food evenly, does not allow the heat of the heat source to be concentrated at a certain portion of the food for a long time. Therefore, when the rotating grill rack 1 is used to grill relatively chunky food (e.g., thick beef stake and turkey wings), the food tends to be cooked only on the outside but raw inside and hence requires more cooking time. The issue to be addressed by the present invention is to design a driving device which can control the rotating grill rack in such a way that, after being rotated for a predetermined amount of time, the rotating grill rack pauses (i.e., stops rotating) above the heat source for a while to heat a certain portion of the food longer.